U.S. Pat. No. 6,604,327 (Reville) discloses a retractable trackless spa enclosure including at least two sections, a first section being slightly smaller than a second section. The first section may be retracted into the second section in reverse telescoping fashion. Both sections are mounted on wheels so that the spa may be more easily moved. Both sections of the enclosure may also include a sliding door for access/egress. In addition, the front end panel of the front section is pivotally mounted on rollers that move within a track. The pivotal mounting allows the front end panel to be rotated in its frame, so that it can be moved to a position horizontal to the ground, thereby providing sufficient clearance for the enclosure to pass over the spa. When the enclosure is retracted, the front end panel can be moved to a position adjacent the end wall of the rear section, so that an open-ended alcove is formed. The frame of the structure is formed from extruded aluminum, and is therefore very lightweight. The roof utilizes unique purlins that enable the roof to meet snow load requirements with a minimum of material. The panels inserted into the frame will typically be clear plastic.
U.S. Pat. No. 4,175,361 (Kumode) discloses an openable canopy housing having a series of movable, telescoping, transparent and arched panels which form the combination roof and sides. Part of the roof of the housing is formed by a horizontal beam, which extends the length of the structure. The transparent panels can be selectively opened or closed to provide a structure, which can be used for indoor as well as outdoor use.
U.S. Pat. No. 6,637,160 (Brooks) discloses a plurality of movable transparent arcuate sections that can roll on their own designated tracks to enclose or expose a sun room or pool area. The enclosure comprises a plurality of overlapping transparent arcuate arches or sections positioned on parallel tracks. The arches can be selectively moved to any position on the parallel tracks. The two distal end arches have removable end closure panels. Each of the transparent panel members or the arches are positioned within a frame member having a plurality of wheels engaging the spaced apart track members. Track members are fixedly positioned to the ground or foundation structures in a spaced-apart parallel configuration. Each side of an arch consists of a plurality of wheels fixedly positioned between spaced apart track elements having hook-like terminations to prevent dislocation of the frame member from the track member. Each arch is slidably positioned on its respective track before plugs are inserted into the distal end of each track rail.
U.S. Pat. No. 5,907,928 (Charbonnel) discloses a removable protective shelter. It comprises a substantially rigid frame and a substantially watertight cover. The frame and cover form a plurality of telescopic shelter elements, every shelter element being assembled on watertight slides with regard to another adjacent shelter element by means of at least another roller-guiding system allowing the overall and relative movement of all shelter elements with regard to each other in particular with no lateral play. The shelter can be used for the protection of swimming pools, terraces, and the construction of mobile verandas.